1. Technical Field
The present invention is directed to a detection system and method for increasing sensitivity and rapidity of the detection system, and more particularly, to increasing fluorescence detection in surface assay systems while increasing kinetics of a bioreaction in the detection system.
2. Background of Related Art
Immunoassays are used widely for the detection and determination of a variety of proteins, peptides and small molecules.1−8 While there exists a large diverse family of immunoassays today, the basic principles are mostly the same.1−8 These typically use antigen-antibody binding for analyte recognition and mostly fluorescence based readout for signal transduction. Fluorescent based immunoassays are available in many forms, such as time-resolved immunoassays,9−13 energy transfer immunoassays14−16 and fluorescence polarization immunoassays.17, 18 The antigen-antibody recognition step is most often kinetically very slow, requiring long incubation times, very few assays subsequently being complete less than 10 minutes.1−8 In addition, the sensitivity of fluorescence based immunoassays is mostly governed by the quantum yield of the tagging fluorophore and the efficiency and sensitivity of the detection system.1−-8 These two physical constraints underpin both the rapidity and sensitivity of current immunoassays.1−8 
The present inventor, along with his colleagues, discovered that close-proximity to metallic silver islands or colloids can alter the radioactive decay rate and/or excitation rate of fluorophores. Further, it has been shown that quantum yield of low quantum yield fluorophores can be increased by proximity to metallic surfaces. The enhanced excitation of fluorophores in close proximity to metallic surfaces including nanostructures, islands, colloids, porous and continuous surfaces can have numerous applications in the biochemical and biological applications of fluorescence because of the increased intensity of the fluorescence.
Fluorescence detection is the basis of most assays used in drug discovery and high throughput screening (HTS) today. In all of these assays, assay rapidity and sensitivity is a primary concern. The sensitivity is determined by both the quantum yield of the fluorophores and efficiency of the detection system, while rapidity is determined by the physical and biophysical parameters of temperature, concentration, assay bioaffinity etc.
However, the assays and system discussed hereinabove, are limited by the reaction time of the chemical reactions within the assays, such as that which occur in binding or hybridization. Thus, there is a need for assay systems and methods that increase the biological/biochemical kinetics of the reaction, increase the sensitivity and that can be used for in both clinical and emergency room assessments.